Arch form and dimensional changes in orthodontics.

The dental arch form is a composite of individual tooth position; alteration in arch dimensions may be planned to alleviate crowding, to address transverse discrepancies and may be considered to enhance smile aesthetics. Characteristic changes in arch dimensions occur throughout life including a reduction in transverse dimensions and arch length; increases in transverse dimensions are typical during orthodontic treatment. In this paper the literature relating to arch dimensional changes arising naturally with growth and produced by orthodontic treatment is reviewed and discussed.